Find all School-related info fast with the new School-Specific MBA Forum

It is currently 18 Apr 2014, 23:09

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Machine A and Machine B are each used to manufacture 660

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Director
Director
Joined: 16 Aug 2005
Posts: 950
Location: France
Followers: 1

Kudos [?]: 8 [0], given: 0

GMAT Tests User
Machine A and Machine B are each used to manufacture 660 [#permalink] New post 18 May 2006, 18:34
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
Machine A and Machine B are each used to manufacture 660 sprockets. It takes machine A 10 hours longer to produce 660 sprockets than machine B. Machine B produces 10% more sprockets per hour than machine A. How many sprockets per hour does machine A produce

A. 6
B. 6.6
C. 60
D. 100
E. 110

This took me a long time to calculate and figure out. Does anyone have a quick method that you can show me?

Source suggested backsolving due to time constraints.
Manager
Manager
User avatar
Joined: 04 May 2006
Posts: 53
Followers: 1

Kudos [?]: 1 [0], given: 0

 [#permalink] New post 18 May 2006, 18:52
Using POE, answers C, D and E look too big because the difference in time it takes for A and B is [u]only[/u] 10% and it takes [u]10 hrs more [/u] for A than B to make 660.

Now going by backsolving, start with A (as it's easy one without decimals :-D ).

If A makes 6/hr --> B makes 6.6/hr.
It takes A 110 hrs for 660 sprockets (ot whatever they are) and
it takes B 100 hrs for the same.

Hence A.
Manager
Manager
Joined: 28 Mar 2006
Posts: 158
Followers: 1

Kudos [?]: 2 [0], given: 0

 [#permalink] New post 18 May 2006, 18:57
B = x hrs to produce 660
A = x + 10 hrs to produce 660

in one hr B produces 660/x
in one hr a produces 660/x + 10
660/x - 660/x+10 = 1/10(660/x+10)
solving we get x = 100
x + 10 = 110...
Thus Aproduces 660/110 =6 sprockets in an hour.

I couldnt think of a faster approach, but the above one dint take much time either.
GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 07 Jul 2004
Posts: 5099
Location: Singapore
Followers: 15

Kudos [?]: 120 [0], given: 0

GMAT Tests User
 [#permalink] New post 18 May 2006, 22:05
Machine B: Takes x hours to produce 660 sprockets
Machine A: Takes (x+10) hours to produce 660 sprockets

Machine B: In 1 hour, B makes 660/x sprockets
Machine A: In 1 hour, A makes 660/(x+10) sprockets

Equating:

1.1(660/(x+10)) = 660/x
726/(x+10) = 660/x
726x = 660x+6600
66x = 6600
x = 100

A makes 660/(110) = 6 sprockets per hour
Director
Director
Joined: 24 Oct 2005
Posts: 663
Location: London
Followers: 1

Kudos [?]: 6 [0], given: 0

GMAT Tests User
 [#permalink] New post 19 May 2006, 01:44
We get two equations here for number of sockets by B in 1hr

Let time taken by A for 660 sockets = x

1) B in 1 hr = 1.1 * (a in 1 hr)

ie. 1.1 * 660/x = 726/x

2) B taken 10 hrs less than A for 660 sockets

660 sockets in (x-10) hrs
Therefore 1hr = 660/x-10

Using these two,

726/x = 660/(x-10)

So, x = 110.
In 1 hr A makes 660/110 = 6 sockts
  [#permalink] 19 May 2006, 01:44
    Similar topics Author Replies Last post
Similar
Topics:
New posts Machine A and Machine B are each used to manufacture 660 rahulraao 2 11 Oct 2005, 06:33
This topic is locked, you cannot edit posts or make further replies. New 2 Experts publish their posts in the topic Machine A and machine B are each used to manufacture 660 GMATT73 18 01 Nov 2005, 06:27
New posts Machine A and Machine B are each used to manufacture 660 giantSwan 3 26 Apr 2008, 12:55
Popular new posts 7 Experts publish their posts in the topic Machine A and machine B are each used to manufacture 660 zisis 19 07 Aug 2010, 04:37
New posts 3 Experts publish their posts in the topic Machine A and Machine B are each used to make 660 widgets. summer101 3 04 Aug 2013, 10:47
Display posts from previous: Sort by

Machine A and Machine B are each used to manufacture 660

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.